嵌套表用法详解（PLSQL）

嵌套表

嵌套表是一种类似于索引表的结构，也可以用于保存多个数据，而且也可以保存复合类型的数据

嵌套表指的是一个数据表定义事同时加入了其他内部表的定义，这一概念是在oracle 8中引入的，它们可以使用SQL进行访问，也可以进行动态扩展。

创建表指定嵌套表存储空间名称

Create table 表名称（

字段名称 类型

……

嵌套表字段名称 嵌套表类型

）NESTED TABLE 嵌套表字段名称 STORE AS 存储空间名称；

定义部门表

DROP TABLE department

Create table department(

Did number,

Deptname varchar(30) not null,

Projects project_nested,

Constraint pk_did primary key(did)

)NESTED TABLE projects STORE AS projects_nested_table;

创建新的对象类型

Create type 类型名称 AS OBJECT(

列名称 数据类型，

列名称 数据类型，

……

列名称 数据类型

);

/

范例：创建一个表示项目类型的对象

Create or replace type kingsql_type as object(

Projectid number,

Projectname varchar(50),

Projectfunds number,

Pubdate date

);

/

CREATE OR REPLACE TYPE kingsql_type AS OBJECT(

projectid NUMBER ,

projectname VARCHAR(50),

projectfunds NUMBER ,

pubdate DATE

) ;

定义嵌套表类型——project_nested

CREATE OR REPLACE TYPE kingsql_nested AS TABLE OF kingsql_type NOT NULL ;

CREATE TABLE department_01 (

did NUMBER ,

deptname VARCHAR(50) NOT NULL ,

qt_column kingsql_nested

) NESTED TABLE qt_column STORE AS kingsql_nested_t1((

projectid NOT NULL ,

projectname NOT NULL ,

projectfunds NOT NULL ,

pubdate NOT NULL)) ;

嵌套表插入数据

insert into department_01 values(

1,--第一列

'hehe1',--第二列

kingsql_nested(kingsql_type(1,'hehe1',1,sysdate),kingsql_type(11,'hehe11',11,sysdate))); 第三列第一行/第三列第二行

插入数据

declare

v1 kingsql_nested:=kingsql_nested(kingsql_type(2,'haha2',2,sysdate));

begin

insert into department_01

values(1,'hehe1',kingsql_nested(kingsql_type(1,'hehe1',1,sysdate),kingsql_type(11,'hehe11',11,sysdate)));

insert into department_01 values(2,'haha2',v1);

end;

/

查询嵌套表数据

select * from the(select department_01.qt_column from department_01 where did=1);

PROJECTID PROJECTNAME     PROJECTFUNDS PUBDATE

---------- -------------------------------------------------- ------------ -------------------

1 hehe1  1  2018-05-21 14:35:32

11 hehe11 11 2018-05-21 14:35:32

select * from the(select department_01.qt_column from department_01 where did=2);

PROJECTID PROJECTNAME PROJECTFUNDS PUBDATE

---------- -------------------------------------------------- ------------ -------------------

2 haha2  2  2018-05-21 14:35:32

select * from the(select department_01.qt_column from department_01 where did=1) where projectid=1;

PROJECTID PROJECTNAME  PROJECTFUNDS PUBDATE

---------- -------------------------------------------------- ------------ -------------------

1 hehe1  1  2018-05-21 14:35:32

直接插入嵌套表数据

insert into the(select department_01.qt_column from department_01 where did=1) values(111,'hehe111',111,sysdate);

Select * from the(select department_01.qt_column from department_01 where did=1);

循环插入一百行

declare
x number:=3;
begin
for x in 3..103 loop
insert into the(select department_01.qt_column from department_01 where did=2) values(x,'hehe',111,sysdate);
end loop;
commit;
end;

直接更新嵌套表数据

update the(select department_01.qt_column from department_01 where did=1) set projectid=1111 where projectid=1;

commit;

select * from the(select department_01.qt_column from department_01 where did=1)

直接删除嵌套表数据

delete the(select department_01.qt_column from department_01 where did=1) where projectid=1111;

commit;

select * from the(select department_01.qt_column from department_01 where did=1);

DROP TABLE department_01 PURGE ; 从回收站删除